1. Field of the Invention
The present invention relates to a printing system, printing apparatus, and printing control method for printing out print data sent from, e.g., a host computer.
2. Description of the Related Art
Conventionally, a page printer dedicated to image output is known, and is called a host-based printer.
In this printer, a host computer compresses mapped image data for one page in turn from the head of a page, and sends the compressed data to a controller unit of the printer. The controller unit expands the received compressed data in turn, converts the expanded data into a video signal, and outputs the video signal to an engine unit in synchronism with the paper discharge timing of the engine unit. In this way, printing on a paper sheet for one page is done.
In such printer, conversion of the compression image data into a video signal and video signal output to the engine unit are done by a hardware circuit. Ultimately, the controller unit does not require any CPU, and a very low-cost page printer can be provided.
However, the host computer that uses the conventional host-based printer temporarily maps all print data such as character print data, figure draw data, image paste data, and the like as images, then compresses the mapped images, and transfers the compressed data to the printer. For this reason, the volume of data to be transferred from the host computer to the printer becomes large. Also, since the host computer must temporarily map all data as images, especially, a plurality of pages of documents take a long processing time on the host computer, resulting in long print processing time.